To begin with items to begin with: It really is illegal to utilize a flammable refrigerant to recharge an automotive air conditioning system. There are some exceptions, such as the new HFO-1234YF refrigerant, and that is mildly flammable below particular problems. Flammable refrigerants may perhaps also be utilized inside the trailer refrigeration units on hefty duty trucks. But besides these, no flammable refrigerant must ever be made use of inside a car or light truck A/C system.

Fire Hazard

Propane, butane plus a quantity of other hydrocarbon mixtures and blends basically do the job rather effectively as refrigerants, with cooling qualities comparable to R-12, R-22 and R-134a. But if the evaporator in the passenger compartment develops a leak, the flammable vapor may well make a possible for any fire or explosion. Do you really desire to chance currently being cremated whilst driving your automobile?

A further imagined to help keep in mind is what transpires in case your vehicle is involved with an accident. The A/C condenser sits correct in front of the radiator and consists of substantial pressure refrigerant vapor and liquid. If your condenser is ruptured inside a frontal collision (which it typically is), higher strain flammable vapor shall be released, just about guaranteeing an underhood fire!

Do you genuinely would like to chance your life or even the lives of one’s passengers by utilizing a cheap flammable refrigerant inside your vehicles air conditioning system? R-134a is definitely the only refrigerant that needs to be used when recharging a late model automotive A/C system.


The US EPA SNAP regulations tend not to make it possible for using flammable refrigerants in motor vehicles.

The only exception is actually a new refrigerant referred to as HFO-1234yf that is only mildly flammable beneath certain circumstances and is not even in production yet.

The Mobile Air Conditioning Society (MACS) also won’t approve of utilizing flammable refrigerants. Nor does the Society of Automotive Engineers (SAE). Like the EPA SNAP guidelines, the only exception will be the new HFO-1234yf refrigerant that should start appearing in some new cars in 2013 or past as a replacement for R-134a.

Use R-134a Only

The EPA, MACS and SAE all say that the only acceptable replacement refrigerant for newer R-134a system is R-134a. Nothing else need to be employed to prevent cross-contamination problems and cooling efficiency difficulties. Older cars with R-12 could be retrofitted with R-134a or other approved alternative refrigerants (which also need to NOT be flammable).

Right here is document that includes many superior information regarding choice refrigerants, although it truly is dated 1999. The basic data is unchanged, along with the only update will be the approval of HFO-1234YF for long term A/C techniques.

Flammable Refrigerants are Against the Law!

Numerous city municipalities and states have laws prohibiting the use of flammable refrigerants in motor vehicles.

In Europe, propane is permitted in some home refrigerators, but the total is so little that it poses no explosion or fire hazard. Refrigerators need to also pass safety tests that display any refrigerant leak can’t produce a fire or explosion hazard.

OZ-12 and HC-12A

Alternate refrigerants that usually do not meet the EPA’s criteria for environmental acceptability or security incorporate OZ-12, HC-12a, R-176 and R-405a. Flammable refrigerants such as OZ-12 and HC-12a include significant quantities of hydrocarbons (propane, butane, isobutane, etc.) and also have been declared illegal for use in mobile A/C applications but are nevertheless acquiring their way into A/C techniques due to their inexpensive value.

The EPA does not approve of flammable refrigerants since the EPA says they pose a significant danger to a vehicle’s occupants need to a leak come about. The EPA says a spark from a cigarette or even a switch could ignite leaking refrigerant creating an explosion and fire.

Counterpoint: The makers of HC-12a contend the flammability danger is remarkably exaggerated and there may be “no evidence” to support claims that a cigarette or spark can ignite their merchandise. Additionally they contend that the EPA’s place on their solution is unfair, and that HC-12a continues to be successfully employed in lots of vehicle A/C systems worldwide without any accidents or injuries as a result of ignition.


A further choice refrigerant that has been proposed for automotive use is HFC-152a. It’s a GWP rating of 140, which meets the European requirements for combating world wide warming. HFC-152a has cooling traits very close to that of R-134a, and could most likely be used as a direct substitute for R-134a with handful of if any modifications. But HFC-152a is flammable, so it truly is at this time illegal to work with.

One achievable solution to your flammability matter HFC-152a (or other flammable refrigerants) is usually to add a leak sensor inside the automobile that warns the passengers if a leak takes place, and instantly opens the power windows to vent the vapors (therefore, minimizing the fire/explosion chance).

A different remedy should be to redesign the A/C system to ensure that it makes use of a “secondary loop” to keep the flammable refrigerant during the engine compartment and from the passenger compartment. With this strategy, the refrigerant circulates by an intermediate warmth exchanger and chills a liquid (almost certainly a water/antifreeze mixture) that then flows throughout the HVAC unit inside the car. A modern report in the U.S. EPA says this tactic meets its security criteria, even though also staying vitality efficient. But it isn’t going to decrease the chance of fire within a frontal collision, and it nonetheless poses a threat to technicians and do-it-yourselfers though recharging or servicing the A/C system.


The newest alternate refrigerant is HFO-1234yf. The refrigerant will at some point substitute R-134a, starting in model yr 2013 on some autos. It has thermal traits which have been related to R-134a, so no major modifications towards the A/C system are crucial. It’s a lower GWP rating of significantly less than 150, which meets the European specifications for lessening worldwide warming. Nevertheless it is mildly flammable (though significantly significantly less so than HFC-152a) and can only melt away below a number of situations (which should really NOT come about in standard automotive use).